Ajmurf

My truck is making a whining noise when the engine is turned on, gas is pressed, and when I release it as well. Its almost like the tune of the whining stays in tune with the rpm level of the motor. For example, I press the gas, and the whining gets louder and stays in tune with the motor, and when I let off the gas and coast, then it whines down with the motor. This has been happening for about a week now. Looking for help